Campbell Scientific CS440 Liquid Level Sensor User Manual
Page 12
CS440 Liquid Level Sensor
8
Suggestion:
A kinked or plugged vent tube will not effectively vent a gauge pressure
(vented) type of device. Normal changes in barometric pressure will appear as
water level fluctuations and these types of errors are typically on the order of 1
foot of water level. If the desiccant chamber has not been properly maintained,
water may have condensed in the vent tube and the device should be returned
to the factory for service.
Note that errors in uncompensated depth measurement using absolute (non-
vented) devices are expected and may or may not be significant, depending on
the application. A barometric pressure transducer can be used to provide
compensation data, effectively eliminating error due to barometric fluctuations.